To protect passengers in a vehicle, such as an automobile, against injury in the event of a collision, the potentially injurious effects of the high deceleration forces acting on the vehicle, as a result of the collision, must be moderated. One commonly practiced method of moderating the effects is to hold the vehicle passengers securely against portions of the vehicle, such as it seats. The passengers thus decelerate at essentially the same instant and at the same rate as the vehicle and are not "thrown", as a result of differing times or rates of deceleration, against parts of the vehicle interior.
The most widely used device for securely holding a passenger in an automobile is a safety belt that straps the passenger firmly to his seat. A safety belt may include a single belt or strap arranged to extend across a passenger's lap or diagonally across his body from one shoulder to the opposite hip. Another type of safety belt, designated a three-point safety belt, includes two belts or straps which are joined together so that only three connections are necessary to secure the ends of the belts to the automobile. Generally, a three-point safety belt is a combination lap belt and diagonal shoulder belt.
A commonly owned, copending patent application, Ser. No. 401,680, filed Sept. 28, 1973, now U.S. Pat. No. 3,931,988, patented Jan. 13, 1976, describes and illustrates a safety device for vehicle passengers which includes a restraint, such as a shoulder belt, for the upper portion of a passenger's body and an energy absorbing impact element disposed on the vehicle adjacent the passenger's knees. The shoulder belt, or a functionally similar device, affords protective restraint for the upper portion of the passenger's body, while the lower portion of his body is protected by the impact element. The inventive safety device of application Ser. No. 401,680 is particularly suited for use as a passive safety device in which one end of the shoulder belt is located on a door adjacent the vehicle seat associated with the device. Such a passive safety device does not require the user to handle the safety belt upon entering or leaving the vehicle.
The illustrated embodiment of the impact element of application Ser. No. 401,680 is fabricated of two lengths of sheet metal formed with M-shaped cross sections. A similar impact element having a different, generally U-shaped cross section is described and illustrated in commonly-owned, copending patent application Ser. No. 486,864, filed July 9, 1974.
In addition to the impact elements for a passenger's knees described and illustrated in the patent applications identified above, various energy absorbing impact elements for the upper portion of a passenger's body have been proposed. Examples of such impact elements are described and illustrated in the following United States patents: Smith U.S. Pat. No. 3,468,556, Akiyama U.S. Pat. No. 3,806,154, Stegmaier U.S. Pat. No. 3,774,713, Glance U.S. Pat. No. 3,831,705, Wilfert U.S. Pat. No. 3,817,553 and Sobkow U.S. Pat. No. 3,614,128.